This is the seventh paper in the evidence-based medicine glossary series. In this paper, We mainlyintroduced five terms related to meta-analysis——prospective meta-analysis, individual patient data meta-analysis,cumulative meta-analysis, multiple-treatments meta-analysis and meta regression.We also gave some examples to helpreaders better understand and use them.
Objective To analysis correlation factors for preoperative sudden death of patients with type A aortic dissection in order to determine clinical management strategy.?Methods?We retrospectively analyzed clinical data of 52 patients with type A aortic dissection who were admitted in Department of Cardiothoracic Surgery of the Affiliated Drum Tower Hospital of Nanjing University Medical School from January 2003 to January 2010. According to the presence of preoperative death, all the patients were divided into two groups, 9 patients in the preoperative sudden death （PSD）group including 7 males and 2 females with their mean age of 52.0±12.1 years；43 patients in the control group including 31 males and 12 females with their mean age of 51.5±10.9 years. Univariate and multivariate logistic regression analysis were used for analysis of preoperative factors related to sudden death.?Results?Univariate analysis result showed 7 candidate variables：body mass index （BMI, Wald χ2=2.150, P=0.143）, time of onset （Wald χ2=2.711, P= 0.100）, total cholesterol （TC, Wald χ2=1.444, P=0.230）, low density lipoprotein cholesterol （L-C, Wald χ2=1.341, P=0.247）, aortic insufficiency （AI, Wald χ2=2.093, P=0.148）, aortic sinus involvement （Wald χ2=3.386, P=0.066）and false lumen thrombosis （Wald χ2=7.743, P=0.005）. Multivariate logistic regression analysis showed that BMI （Wald χ2=4.215, P=0.040, OR=1.558）and aortic sinus involvement （Wald χ2=4.592, P=0.032, OR=171.166 ）were preoperative risk factors for sudden death, and thrombosed false lumen （Wald χ2=5.097, P=0.024, OR=0.011）was preoperative protective factor for sudden death.?Conclusion?Type A aortic dissection patients with large BMI and/or aortic sinus involvement should receive operation more urgently than others and patients with thrombosed false lumen may have relatively low risk of preoperative sudden death.
Objective To investigate the clinical features, treatment methods, and prognostic influence factors of patients with malignant peripheral nerve sheath tumor (MPNST). MethodsA retrospective analysis was conducted on 96 MPNST patients treated between January 1, 2015 and December 31, 2021. There were 46 males and 50 females, aged between 15 and 87 years (mean, 48.2 years). The tumors were located in the trunk in 50 cases, extremities in 39 cases, and head and neck in 7 cases. The maximum tumor diameter was <5 cm in 49 cases, ≥5 cm in 32 cases, with 15 cases missing data. Tumor depth was deep in 77 cases and superficial in 19 cases. The Fédération Nationale des Centres de Lutte Contre le Cancer (FNCLCC) histological grading was G1 in 9 cases, G2 in 12 cases, and G3 in 34 cases, with 41 cases missing data. There were 37 recurrent MPNST cases, 32 cases with neurofibromatosis type 1 (NF1), and 26 cases in stage Ⅳ. Postoperative adjuvant radiotherapy was administered to 25 patients, perioperative chemotherapy to 45 patients, and anlotinib-targeted therapy to 30 patients. R0 resection was achieved in 73 cases. Patients were divided into groups based on the presence or absence of NF1, and baseline data between the two groups were compared. Kaplan-Meier curves were generated to assess disease-free survival (DFS) and overall survival (OS) based on various factors (age, gender, presence of NF1, recurrent MPNST, stage Ⅳ MPNST, FNCLCC grade, R0 resection, tumor location, tumor size, tumor depth, perioperative chemotherapy, postoperative adjuvant radiotherapy, and anlotinib-targeted therapy), and differences between survival curves were analyzed using the Log-Rank test. Multivariate COX proportional hazards regression was used to identify independent prognostic factors for MPNST. Results Patients with NF1 had a significantly higher proportion of superficial tumors and lower FNCLCC grade compared to those without NF1 (P<0.05); no significant difference was found for other variables (P<0.05). Kaplan-Meier analysis showed that recurrent MPNST, stage Ⅳ MPNST, FNCLCC grade, R0 resection, perioperative chemotherapy, and anlotinib-targeted therapy were factors influencing 1-year DFS (P<0.05), while stage Ⅳ MPNST, FNCLCC grade, and perioperative chemotherapy were factors affecting 3-year OS (P<0.05). Multivariate COX proportional hazards regression analysis revealed that recurrent MPNST and high-grade FNCLCC (G3) were independent prognostic factors for 1-year DFS (P<0.05), while stage Ⅳ MPNST, superficial tumor depth, age over 60 years, postoperative adjuvant radiotherapy, and anlotinib-targeted therapy were independent prognostic factors for 3-year OS (P<0.05). Conclusion MPNST patients with NF1 tend to have more superficial tumors and lower FNCLCC grades. FNCLCC grade, R0 resection, and adjuvant therapies, including radiotherapy and anlotinib-targeted therapy, are closely associated with MPNST prognosis. Complete surgical resection should be prioritized in clinical management, along with adjuvant treatments such as radiotherapy and targeted therapy of anlotinib to improve patient outcomes.
ObjectiveTo investigate the association of preoperative serum uric acid (UA) levels with postoperative prolonged mechanical ventilation (PMV) in patients undergoing mechanical heart valve replacement.MethodsClinical data of 311 patients undergoing mechanical heart valve replacement in The First Affiliated Hospital of Anhui Medical University from January 2017 to December 2017 were retrospectively analyzed. There were 164 males at age of 55.6±11.4 years and 147 females at age of 54.2±9.8 years. The patients were divided into a PMV group (>48 h) and a control group according to whether the duration of PMV was longer than 48 hours. Spearman's rank correlation coefficient and logistic regression analysis were conducted to evaluate the relationship between preoperative UA and postoperative PMV. The predictive value of UA for PMV was undertaken using the receiver operating characteristic (ROC) curve..ResultsAmong 311 patients, 38 (12.2%) developed postoperative PMV. Preoperative serum UA level mean values were 6.11±1.94 mg/dl, while the mean UA concentration in the PMV group was significantly higher than that in the control group (7.48±2.24 mg/dl vs. 5.92±1.82 mg/dl, P<0.001). Rank correlation analysis showed that UA was positively correlated with postoperative PMV (rs=0.205, P<0.001). Multivariate logistic regression analysis demonstrated that preoperative elevated UA was associated independently with postoperative PMV with odds ratio (OR)=1.44 and confidence interval (CI) 1.15–1.81 (P=0.002). The area under the ROC curve of UA predicting PMV was 0.72, 95% CI0.635–0.806, 6.40 mg/dl was the optimal cut-off value, and the sensitivity and specificity was 76.3% and 63.0% at this time, respectively.ConclusionPreoperative elevated serum UA is an independent risk factor for postoperative PMV in patients undergoing mechanical heart valve replacement and has a good predictive value.
ObjectiveTo investigate the risk factor for restenosis of esophageal anastomosis stricture after esophageal cancer operation. MethodsWe retrospectively analyzed the clinical data of 83 patients including 61males and 22 females at age of 58.9(41-81) years with esophageal anastomoic stricture after esophageal cancer operation between January 2002 and December 2013. According to whether the patients developed to restenosis or not, the statistical test and logistic regression was conducted to analyze the risk factors for restenosis. ResultsIn the 83 patients with esophageal anastomoic stricture after esophageal cancer surgery, 35 patients (42.2%) experienced restenosis within the following-up of 1 year. The result of logistic regression analysis indicated that restenosis appeared in 3 months (Wald value=23.3, P < 0.001), the interval between two subsequent sessions of more than 4 weeks at each esophagus dilatation(Wald value=4.8, P=0.029) and the stricture diameter of less than 12 mm after dilation (Wald value=5.8, P=0.016) are the independent risk factors for restenosis in esophageal anastomotic stricture. ConclusionFor the patients with esophageal anastomoic stricture after esophageal cancer operation, we believe that it's conducive to reduce esophageal restenosis if the interval between dilations is within 4 weeks and the diameter of stricture after dilation can reach above 12 mm.
ObjectiveTo investigate the correlative factors for the efficacy of surgical treatment for single segment degenerative lumbar spinal disorders. MethodsFrom October 2008 to November 2010, a prospective non-randomized controlled study was carried out on 179 patients who were diagnosed to have L4-5 degenerative lumbar spinal disorders and underwent surgical treatment. Ninety-seven patients were included in our study, including 64 males and 33 females, aged between 21 and 86 years old, averaging 49.0. The follow up lasted for an average of 18.9 (12-27) months. The correlative factors including age, sex, body mass index, preoperative psychological state and degree of low back pain, surgical methods, combination with adjacent segment degeneration and recurrence state were analyzed. Single and multiple-factor Logistic regression analysis was used to determine the relationship between independent factors and surgical results of lumbar degenerative disease. ResultsAt the last follow-up, Japanese Orthopaedic Association scores were improved to 22.40±3.18 with an improving rate of (68.5±15.7)% compared with the preoperative condition (7.61±3.09), and the difference was significant (t=-33.031, P<0.001). Univariate analysis showed that all factors were variables associated with the surgical results excluding sex and age (P<0.05). Multiple-factor logistic regression analysis showed that the preoperative psychological state, combination with adjacent segment degeneration and surgical methods had important impact on the surgical results (P<0.05). ConclusionSurgical treatment of lumbar degenerative disease is effective. The preoperative psychological state, combination with adjacent segment degeneration and surgical methods are important factors associated with the surgical results.
Signal classification is a key of brain-computer interface (BCI). In this paper, we present a new method for classifying the electroencephalogram (EEG) signals of which the features are heterogeneous. This method is called wrapped elastic net feature selection and classification. Firstly, we used the joint application of time-domain statistic, power spectral density (PSD), common spatial pattern (CSP) and autoregressive (AR) model to extract high-dimensional fused features of the preprocessed EEG signals. Then we used the wrapped method for feature selection. We fitted the logistic regression model penalized with elastic net on the training data, and obtained the parameter estimation by coordinate descent method. Then we selected best feature subset by using 10-fold cross-validation. Finally, we classified the test sample using the trained model. Data used in the experiment were the EEG data from international BCI Competition Ⅳ. The results showed that the method proposed was suitable for fused feature selection with high-dimension. For identifying EEG signals, it is more effective and faster, and can single out a more relevant subset to obtain a relatively simple model. The average test accuracy reached 81.78%.
Portal hypertension (PHT) is a common complication of liver cirrhosis, which could be measured by the means of portal vein pressure (PVP). However, there is no report about an effective and reliable way to achieve noninvasive assessment of PVP so far. In this study, firstly, we collected ultrasound images and echo signals of different ultrasound contrast agent (UCA) concentrations and different pressure ranges in a low-pressure environment based on an in vitro simulation device. Then, the amplitudes of the subharmonics in the echo signal were obtained by ultrasound grayscale image construction and fast Fourier transform (FFT). Finally, we analyzed the relationship between subharmonic amplitude (SA) and bionic portal vein pressure (BPVP) through linear regression. As a result, in the pressure range of 7.5–45 mm Hg and 8–20 mm Hg, the linear correlation coefficients (LCC) between SA and BPVP were 0.927 and 0.913 respectively when the UCA concentration was 1∶3 000, and LCC were 0.737 and 0.568 respectively when the UCA concentration was 1∶6 000. Particularly, LCC was increased to 0.968 and 0.916 respectively while the SAs of two UCA concentrations were used as the features of BPVP. Therefore, the results show a good performance on the linear relationship between SA and BPVP, and the LCC will be improved by using SAs obtained at different UCA concentrations as the features of BPVP. The proposed method provides reliable experimental verification for noninvasive evaluation of PVP through SA in clinical practice, which could be a guidance for improving the accuracy of PVP assessment.
ObjectivesTo analyze the balance of medical human resource allocation in Chengdu and to discuss the impact of human resource allocation structure on the hospital’s medical service capabilities, so as to provide a theoretical basis for the hospital to optimize the talent team structure.MethodsThe Moran’s index and Gini coefficient were used to evaluate the spatial aggregation and grade distribution difference of human resources allocation, respectively. The case mix index (CMI), the length of hospital stay, and the difficulty of surgery were used as outcome variables, and a multiple regression analysis model was established to explore the impact of human resource indicators on the hospital’s medical service capabilities.ResultsThe distribution of doctors showed an obvious spatial aggregation in Chengdu, and there was a positive spatial correlation (Moran’s Idoctor=0.290); the distribution of nurses had no obvious spatial aggregation (Moran’s Inurse=0.102). Under different medical service capacity segments, the Gini coefficient of doctors was 0.518, and the Gini coefficient of nurses was 0.576, both exceeding 0.5, indicating that the distribution of medical human resources in different levels of hospitals was considerably different. The regression results showed that the expansion of the quantity of senior title doctors and the proportion of medical care both could improve the hospital’s CMI. The increase in the quantity of doctors with senior titles also had a certain impact on improving the hospital’s surgical capabilities. The expansion of the proportion of medical care could lead to a slight increase in the length of patients' hospital stay.ConclusionsOptimizing the allocation structure of medical human resources in different regions and hospitals with different levels is an important task in the construction of a hierarchical diagnosis and treatment system. It is necessary to further integrate medical human resources throughout the whole city and strengthen personnel training and team building in primary health institutions. Hospitals at different levels should implement their own development positioning and further optimize their human resource allocation structure according to development needs. Tertiary hospitals should pay more attention to the cultivation of senior professional doctors, optimize the proportion of medical care, and improve the hospital’s medical service capabilities. The primary health institutions should pay attention to the comprehensive construction of medical personnel, and strengthen the development of the team of general practitioners, so as to achieve a comprehensive improvement of the city’s medical service capabilities.
ObjectiveTo explore the risk factors for postoperative respiratory failure (RF) in patients with esophageal cancer, construct a predictive model based on the least absolute shrinkage and selection operator (LASSO)-logistic regression, and visualize the constructed model. MethodsA retrospective analysis was conducted on patients with esophageal cancer who underwent surgical treatment in the Department of Thoracic Surgery, Sun Yat-sen University Cancer Center Gansu Hospital from 2020 to 2023. Patients were divided into a RF group and a non-RF (NRF) group according to whether RF occurred after surgery. Clinical data of the two groups were collected, and LASSO-logistic regression was used to optimize feature selection and construct the predictive model. The model was internally validated by repeated sampling 1000 times based on the Bootstrap method. ResultsA total of 217 patients were included, among which 24 were in the RF group, including 22 males and 2 females, with an average age of (63.33±9.10) years; 193 were in the NRF group, including 161 males and 32 females, with an average age of (62.14±8.44) years. LASSO-logistic regression analysis showed that the percentage of forced expiratory volume in one second/forced vital capacity (FEV1/FVC) to predicted value (FEV1/FVC%pred) [OR=0.944, 95%CI (0.897, 0.993), P=0.026], postoperative anastomotic fistula [OR=4.106, 95%CI (1.457, 11.575), P=0.008], and postoperative lung infection [OR=3.776, 95%CI (1.373, 10.388), P=0.010] were risk factors for postoperative RF in patients with esophageal cancer. Based on the above risk factors, a predictive model was constructed, with an area under the receiver operating characteristic curve of 0.819 [95%CI (0.737, 0.901)]. The Hosmer-Lemeshow test for the calibration curve showed that the model had good goodness of fit (P=0.527). The decision curve showed that the model had good clinical net benefit when the threshold probability was between 5% and 50%. Conclusion FEV1/FVC%pred, postoperative anastomotic fistula, and postoperative lung infection are risk factors for postoperative RF in patients with esophageal cancer. The predictive model constructed based on LASSO-logistic regression analysis is expected to help medical staff screen high-risk patients for early individualized intervention.